10. Because of their popularity, birds provide a terrific doorway to learning about the natural world.

11. Birders pump about $38 billion into the U.S. economy each year, producing about 671,000 jobs. If you include indirect and induced contributions to the economy, the value rises to about $82 billion. (Source: U.S. Fish & Wildlife Service)

12. Learning about birds is a great way for young children to reconnect with the outdoors and avoid Nature Deficit Disorder.

13. The plight of declining bird species was a major driver in the passage of the nation's first wildlife protection laws, and continued to be a major influence leading up to the passage of the U.S. Endangered Species Act of 1973. There are currently 90 birds listed as Threatened or Endangered under the Endangered Species Act. (Source: USFWS)

14. An image of a bird is perhaps the most common symbol ever used on American coins and paper currency.

15. Three Major League baseball teams are named for birds, as are five NFL football teams, four NHL hockey teams, and one NBA basketball team. (And we're not counting the Raptors, Redwings, or Flyers)

16. Their song is one of the most beautiful sounds in nature.

17. Literary experts have counted as many as 600 different references to birds in the works of William Shakespeare - including 45 to 60 different bird species. For example: "Light thickens, and the crow/Makes wing to the rooky wood - Macbeth.

18. Some birds have been around a very long time. For instance, the California Condor has its origins in the Pleistocene era, which ended nearly 12,000 years ago.

19. Birds can be amazingly tough. For instance, the Blue-winged Teal can survive in temperatures as low as -58 degrees Fahrenheit and as high as 122 degrees.

20. The California Department of Fish and Game, in collaboration with conservation groups, identified 74 bird Species of Special Concern in California, which have not been listed or given official conservation status, but whose California populations are nonetheless considered at-risk.

21. The California list of Threatened or Endangered Species contains 29 bird species and subspecies.

23. Of the three icons displayed on the California version of the U.S. 25-cent piece, one is a bird: the California Condor.

24. Admit it, you wish you could fly, too.

25. Teddy Roosevelt was a birder.

26. Birds provide natural insect pest control.

27. Birds, such as hummingbirds, play a vital role in natural pollination.

28. Bird species that are listed as threatened or endangered often provide the only legal means to protect dwindling habitat areas. Protections that have been put into place for the Marbled Murrelet and the Spotted Owl, for instance, are all that stands in the way of the destruction of the West Coast's old growth forests.

29. A birdy, in golf, is a very good thing.

30. One of the classic bird songs of all time, the Trashmen's "Surfin' Bird" reached No. 4 on the Billboard charts in 1963. The song was a combination of the Rivington's R&B singles "Papa-Oom-Mow-Mow" and "The Bird's the Word."